Small Signal Modeling of Electrolyzers and Their Interaction with Power System Dynamics

This research investigates the integration of large- scale electrolyzers into the power grid, focusing on the dynamic behavior and the small signal stability of the system. It presents a comprehensive and detailed modeling framework covering linear and nonlinear electrolyzer models. The model captures the current-voltage relationship by using both fundamental equations and empirical results. Combined with the control systems for the AC and DC side, this results in a comprehensive dynamic model. Analytical and simulation results reveal the decoupling between electrolyzer dynamics, the AC-DC control systems, and the AC power grid. This is demonstrated through three parametric sweeps, which cover the system operating point, the DC-link capacitance of the two-stage conversion, and the short circuit ratio (SCR) of the power grid. These sweeps demonstrate minimal interaction between the different subsystems, proving the robustness of the presented system. The practical implications of this research are significant, as it lays the groundwork for integrating gigawatt-scale electrolyzers with future power grids while ensuring stability.